1. Field of Invention
The present invention relates to a mounting case for accommodating an electro-optical device, such as a liquid crystal panel, which is used as a light valve for a projection display apparatus, such as a liquid crystal projector, an electro-optical device encased in a mounting case, in which the electro-optical device is accommodated, and a projection display apparatus having the electro-optical device encased in the mounting case.
2. Description of Related Art
In general, when a liquid crystal panel is used as a light valve of a liquid crystal projector, the liquid crystal panel is not provided in an exposed state on a console, etc., constituting the liquid crystal projector, but it is accommodated or encased in a suitable mounting case, and then the mounting case including the liquid crystal panel is provided on the console. This is because the liquid crystal panel can easily be fixed to the case by suitably providing screws in the corresponding mounting case.
In the liquid crystal projector, the light emitted from a light source is projected onto the liquid crystal panel encased in the mounting case as focused light. Light passing through the liquid crystal panel is enlarged and projected on the screen to display images. In such a liquid crystal projector, since the enlarged projection is generally predetermined, relatively intense light emitted from a light source such as a metal halide lamp is used.
However, in this construction, first, there is a problem in that the temperature of the liquid-crystal-panel encased in the mounting case, and particularly of the liquid crystal panel rises. The rise in temperature causes a rise in temperature of the liquid crystal interposed between a pair of transparent substrates in the liquid crystal panel. Therefore, the characteristics of the liquid crystal are deteriorated. In addition, when the light emitted from the source light is uneven, the liquid crystal panel is partially heated to generate so called hot spots, and then variations in the transmittance are generated at the hot spots. Thus, the quality of projected images deteriorates.
The technique for preventing the rise in temperature of the liquid crystal panel includes, for example, one disclosed in, for example, International Publication Number WO98/36313, etc. The patent discloses a technique by providing the heat radiating sheet between the liquid crystal panel and a heat radiating plate in the liquid crystal display module comprising the liquid crystal panel and a case (referred as a ‘mounting case’ in this specification) holding and accommodating the liquid crystal panel and having the heat radiating plate. In addition, in order to solve the above problems, other approaches, such as an approach of providing a light shielding film on a substrate positioned at the side of the liquid crystal panel on which light is incident and an approach of forming the mounting case, in which the liquid crystal panel is held or accommodated, using a light reflective material, have been known.